By Jason Snell

September 23, 2020 2:01 PM PT

Fix watchOS upgrade battery problems by unpairing and re-pairing

Note: This story has not been updated since 2020.

Last Wednesday I updated my Apple Watch Series 5 to watchOS 7. And immediately the device’s battery life dropped precipitously.

I’d estimate that in the 11 months since I bought the Series 5, I’d failed to get to the end of the day with battery remaining maybe one time. But every one of the three days after I upgraded to watchOS 7 ended in an early-to-mid-evening demand for Battery Reserve mode from a depleted device.

After complaining about it on Twitter, I received a bunch of suggestions about what to do, most of which I’d categorize as the tech version of folk medicine. Turn off hand washing, or sacrifice a chicken, or stop using sleep tracking (which I hadn’t started using!), or draw a chalk circle around the Apple Watch and hope the spirits went away.

Lots of ideas, but nothing definitive. And then a signal came through the noise—from several people, the suggestion that unpairing the Apple Watch from my iPhone and then re-pairing might solve the issue. Some people reported this solving a similar problem last year, and others said it worked for them this year.

Unpairing and re-pairing is a pain. You have to remove your watch from the list of devices in the Watch app—fortunately, you don’t need to remove the cellular plan from the device and go through that hassle—and then wait as it wipes itself and reboots. Then you have to add it back as if it’s a newly-bought device, and restore it from the backup the Watch app made before un-pairing. It can take quite a while.

But I gave it a go, and you know what? This particular flavor of folk medicine completely worked for me. My Apple Watch is back to normal battery life, running watchOS 7.

I don’t know exactly what’s going on behind the scenes—I suspect that some sort of data sync between the iPhone and the Apple Watch is failing, and retrying, and failing, endlessly. Apple needs to look into it. This doesn’t seem like it’s an isolated issue, but I have no idea how widespread it is. Apple wants its users to stay up to date in terms of device operating systems; a bug like this will do a great job of dissuading a lot of users from ever upgrading again.

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